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Title: QRX 212/75 Problem - Big Problem
Post by: Steve Alves on April 01, 2012, 11:00:36 am
Used my two QRX 212/75's at a St. Patrick's event a few weeks ago. Brand new, first time using them.

At the end of the night before I could turn the amps off, some idiot cut the power. There was a thud through the system but not what I would call extreme.

Fast forward to this weekend, setup and turn everything on and I find I have no mids... I check and triple check everything.. My 218's are passing lows and the horns on the 212's are passing highs but no mids are present (bi-amp system on the 212's).. I quickly reconfigure everything and switch the 212's to passive and still only getting highs through the horn. I grab a Yamaha monitor and connect it in place of the 212 and low and behold I am getting full range (minus the subs going to the 218's).

Is it possible I toasted all 4 of the twelves in the two 212's???

I double, triple, quadruple checked the inputs and the switch position on the 212's..

I am stumped..

Also I bought the 212's new, when I took them out of the box I noticed the grill on one of the has dimples from the little blocks of wood that sits between the speakers to hold out the grill so I was going to see about having that checked. I know it is not related but can the build quality be that bad.


Any thoughts?
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Steve Hurt on April 01, 2012, 02:17:29 pm
Pull a driver and check it w/a meter.
From the search I just ran, the woofers in those cabs seem to blow before the highs do.

They're under warranty aren't they?
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Steve Alves on April 01, 2012, 02:31:55 pm
Pull a driver and check it w/a meter.
From the search I just ran, the woofers in those cabs seem to blow before the highs do.

They're under warranty aren't they?

Only a few weeks old and purchased from an authorized dealer. But does the warranty cover blowing them?
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Tim Weaver on April 02, 2012, 12:01:42 pm
Only a few weeks old and purchased from an authorized dealer. But does the warranty cover blowing them?


Just take it back and say "these don't work". Don't volunteer any more info than that. In the past EV was VERY lenient on their repair policy. I've had many subs reconed that were obviously blown by misuse. I don't know how goos EV's service is now, but it's worth a shot.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Matt Vivlamore on April 02, 2012, 01:35:31 pm
for testing... if you put in a pair of 12's into the holes, do they receive power?

Have you checked the 12's to see if they are "open"?
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Steve Alves on April 02, 2012, 02:07:45 pm
for testing... if you put in a pair of 12's into the holes, do they receive power?

Have you checked the 12's to see if they are "open"?

Have not pulled the drivers yet. I am going to call my dealer and see how they want to handle.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Steven warner on April 02, 2012, 06:39:37 pm
Have not pulled the drivers yet. I am going to call my dealer and see how they want to handle.

build quality should NOT be the problem with these. Pull the drivers and put a meter on them. Ive been through quite a few tops and I love them. They aren't known as having flimsy components either, within reason of course
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Rob Spence on April 03, 2012, 06:04:03 pm
Used my two QRX 212/75's at a St. Patrick's event a few weeks ago. Brand new, first time using them.

At the end of the night before I could turn the amps off, some idiot cut the power. There was a thud through the system but not what I would call extreme.

Fast forward to this weekend, setup and turn everything on and I find I have no mids... I check and triple check everything.. My 218's are passing lows and the horns on the 212's are passing highs but no mids are present (bi-amp system on the 212's).. I quickly reconfigure everything and switch the 212's to passive and still only getting highs through the horn. I grab a Yamaha monitor and connect it in place of the 212 and low and behold I am getting full range (minus the subs going to the 218's).

Is it possible I toasted all 4 of the twelves in the two 212's???

I double, triple, quadruple checked the inputs and the switch position on the 212's..

I am stumped..

Also I bought the 212's new, when I took them out of the box I noticed the grill on one of the has dimples from the little blocks of wood that sits between the speakers to hold out the grill so I was going to see about having that checked. I know it is not related but can the build quality be that bad.
Any thoughts?
Both of my pairs have little dimples too though they are many years old. No one notices.

Since they are brand new, just call the dealer and have em fixed.

For the future, perhaps we can figure out why they died and prevent it from happening again.

What is the signal chain (mixer, eq, crossover, amps) you are using?
Make and model.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Steve Alves on April 03, 2012, 06:16:57 pm
Both of my pairs have little dimples too though they are many years old. No one notices.

Since they are brand new, just call the dealer and have em fixed.

For the future, perhaps we can figure out why they died and prevent it from happening again.

What is the signal chain (mixer, eq, crossover, amps) you are using?
Make and model.


Yamaha 01v96i ---> Driverack 260 with EV recommended settings--->

Each side has a matching amp rack with the following:
Mackie M2600 Bridged Lows - Crown 2500 Bridged Mids - Mackie M800 Stereo Highs

The second channel on the 800's are unused.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Rob Spence on April 03, 2012, 06:30:38 pm

Yamaha 01v96i ---> Driverack 260 with EV recommended settings--->

Each side has a matching amp rack with the following:
Mackie M2600 Bridged Lows - Crown 2500 Bridged Mids - Mackie M800 Stereo Highs

The second channel on the 800's are unused.
I am not familiar with the amp you are using on the mids. Is there more info on the model? I use a QSC PLX3402 on my mids - one cabinet per channel.
Where are the gains on the amp set? I prefer to leave mine wide open or clockwise so if someone were to change something, the most would be it would et quieter.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Steve Alves on April 03, 2012, 06:35:50 pm
I am not familiar with the amp you are using on the mids. Is there more info on the model? I use a QSC PLX3402 on my mids - one cabinet per channel.
Where are the gains on the amp set? I prefer to leave mine wide open or clockwise so if someone were to change something, the most would be it would et quieter.

http://www.crownaudio.com/amp_htm/xls_drivecore.htm (http://www.crownaudio.com/amp_htm/xls_drivecore.htm)

All amps are wide open.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Mike Christy on April 03, 2012, 06:58:39 pm
http://www.crownaudio.com/amp_htm/xls_drivecore.htm (http://www.crownaudio.com/amp_htm/xls_drivecore.htm)

All amps are wide open.

I also run my 212s mids with a PLX3602 on them, never had an issue, although never hard into clipping.

I just wonder if running the budget XLS2500 bridged @ 2 ohms had something to do with it.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Steve Alves on April 03, 2012, 07:10:37 pm
I also run my 212s mids with a PLX3602 on them, never had an issue, although never hard into clipping.

I just wonder if running the budget XLS2500 bridged @ 2 ohms had something to do with it.


Each 212/75 is on it's own amp so it is 4 ohms.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Vinny DAgostino on April 03, 2012, 07:24:08 pm


Each 212/75 is on it's own amp so it is 4 ohms.

Wow.....you have 2400w going to the 12's in that cabinet that are only rated for 600w..
Were you running any limiters?
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Steve Alves on April 03, 2012, 07:27:44 pm
Wow.....you have 2400w going to the 12's in that cabinet that are only rated for 600w..
Were you running any limiters?

I could explain it to you, but then I would have to kill you... ;D
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Vinny DAgostino on April 03, 2012, 07:45:10 pm
I could explain it to you, but then I would have to kill you... ;D

All you would have to explain is if you were running limiters...
Title: QRX 212/75 Problem - Big Problem
Post by: Rob Spence on April 03, 2012, 07:54:39 pm
The previous 3 posters all run QRX212s and we don't use that amount of power.


Sent from my iPhone using Tapatalk
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Steve Alves on April 03, 2012, 08:07:56 pm
The previous 3 posters all run QRX212s and we don't use that amount of power.


Sent from my iPhone using Tapatalk

Using the driverack 260, Looks like Mike has a PLX3602 on his.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Vinny DAgostino on April 03, 2012, 09:03:26 pm
Using the driverack 260, Looks like Mike has a PLX3602 on his.

The 3602 is only 1200w @ 4ohms, I assume he is running (1) cab per channel.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Mike Christy on April 03, 2012, 09:07:21 pm
The 3602 is only 1200w @ 4ohms, I assume he is running (1) cab per channel.

Yup, its just about right, 600W/driver continuous. There is ~2db reserve in the QSC so about 800W, thereabouts.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Steve Alves on April 03, 2012, 09:20:05 pm
Yup, its just about right, 600W/driver continuous. There is ~2db reserve in the QSC so about 800W, thereabouts.

The limiting on the drive rack should handle the overpower but I am guessing when the power was cut to the amps, the thud was 2400 watts into the mids.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: g'bye, Dick Rees on April 03, 2012, 10:01:03 pm
The limiting on the drive rack should handle the overpower but I am guessing when the power was cut to the amps, the thud was 2400 watts into the mids.

I won't claim that this is what happened, but it could be that when the power was cut it was the turn-off spike from the DriveRack hitting the amps while they still had enough of a charge to send the amplified spike to the speakers.  The DR limiting would have no effect at all if it was the unit itself sending the spike.

Another possible reason for having a UPS at FOH........idiot protection for those who'd pull the plug on you.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Tomm Williams on April 04, 2012, 03:22:16 pm
I won't claim that this is what happened, but it could be that when the power was cut it was the turn-off spike from the DriveRack hitting the amps while they still had enough of a charge to send the amplified spike to the speakers.  The DR limiting would have no effect at all if it was the unit itself sending the spike.

Another possible reason for having a UPS at FOH........idiot protection for those who'd pull the plug on you.

Interesting theory, sounds quite plausible.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Matt Vivlamore on April 04, 2012, 05:10:51 pm
The previous 3 posters all run QRX212s and we don't use that amount of power.


Sent from my iPhone using Tapatalk


Well I use an IT4000... but then again I have the RMS limiter is set at 600w @ 4 ohms.  Before that, I was using an XTi4000. 
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Steve Alves on April 05, 2012, 10:09:14 pm
While we are on this topic, how do (2) 212/75's per side over (1) 218 per side sound? Can the single 218's keep up?

I have a deal to get two more and can't make up my mind.

I was also told that it is more likely that something on the internal board probably went and not all 4 drivers. I am waiting for a callback from EV Tech.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Mike Christy on April 06, 2012, 05:58:34 am
While we are on this topic, how do (2) 212/75's per side over (1) 218 per side sound? Can the single 218's keep up?

I have a deal to get two more and can't make up my mind.

I was also told that it is more likely that something on the internal board probably went and not all 4 drivers. I am waiting for a callback from EV Tech.


We've used 6 Growlers center clustered on a PL6 with 2 Qrx212/75s a side, it was just about right. You could conservatively equate a Growler to 1.5 x 18, so with coupling, we had 4 218s, roughly. Depends on the style and venue of course for your needs.

Mike
Title: Re: QRX 212/75 Problem - Big Problem
Post by: John Penkala on April 06, 2012, 07:08:47 am
The limiting on the drive rack should handle the overpower but I am guessing when the power was cut to the amps, the thud was 2400 watts into the mids.

 Cutting power to the amps shouldn't result in blowing speakers. The output relays of the DR260 should open. However, applying phantom power to a wide-open mic could cause this or loosing power at FOH is possibility.

JP
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Rob Spence on April 06, 2012, 04:24:11 pm

We've used 6 Growlers center clustered on a PL6 with 2 Qrx212/75s a side, it was just about right. You could conservatively equate a Growler to 1.5 x 18, so with coupling, we had 4 218s, roughly. Depends on the style and venue of course for your needs.

Mike
So, to amplify, a pair of QRX212 would over run a single 2x18. I would have a pair of 2x18s per side if I were running 2 QRX per side.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Rob Spence on April 06, 2012, 04:27:32 pm
Cutting power to the amps shouldn't result in blowing speakers. The output relays of the DR260 should open. However, applying phantom power to a wide-open mic could cause this or loosing power at FOH is possibility.

JP
The relays "should" open but before the mechanical parts get moving, a pop could get through and the amps would still have plenty of power to do it. I have lost 12" drivers (not in my QRX) before when an unauthorized person powered things down in the wrong order. Some gear put out a nasty pop when powered off.
Title: Re: QRX 212/75 Problem - Big Problem
Post by: Tim Perry on April 06, 2012, 04:48:18 pm
I am not familiar with the amp you are using on the mids. Is there more info on the model? I use a QSC PLX3402 on my mids - one cabinet per channel.
Where are the gains on the amp set? I prefer to leave mine wide open or clockwise so if someone were to change something, the most would be it would get quieter.

Operating the power amps at maximum gain maximizes the ratio between the 'pop" and the signal. 

Turn the driverack outputs up and the amp attenuators down. It will still pop when powered off but wont be nearly as speaker destroying.